Any traceability/tracking system requires some type of labeling or identifiers to be attached on or around the items in question. These can be Barcodes, Stickers, NFC, RFID or any number of other options for tagging physical objects.
In Washington State specifically we are using 16 digit identifiers issued by the State. The State supplied system provides a printed label that includes a C128B barcode as well. The generated documents are PDFs designed to print on small single-shot label printers like a Zebra or Dymo.